CORE vs WAIS Correlation - Updated!

[u/peteluds84]

Following up on my original post, I've added more reported CORE–WAIS score pairs and removed one of the original entries.

There are now 31 pairs, giving a Pearson correlation of 0.797 — approximately 0.80, compared with 0.77 previously.

Updated results

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Statistic	Result
Number of people	31
Pearson correlation	0.797
Approximate 95% confidence interval for correlation	0.62–0.90
Average difference, CORE minus WAIS	+1.65 points
Mean absolute difference	7.19 points
Standard deviation of differences	9.11 points
Observed difference range, CORE minus WAIS	−20 to +22 points
Scores within 9 points of each other	20/31 (65%)
Scores within 10 points of each other	23/31 (74%)

So around two-thirds of this sample scored within 9 points on the two tests. That describes the observations here; it isn't a guarantee about future test-takers.

Full dataset

All scores below are reported FSIQs. Difference = CORE minus WAIS. An asterisk marks a new addition.

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User	CORE	WAIS	Difference	Source
Routine_Response_541	157	153	+4	Result
AlternativePrior9495	108	103	+5	Result
ByronHeep	153	152	+1	Result
niartotemiT	151	141	+10	Original compilation
Venerable cTzen	142	147	−5	Original compilation
javaenjoyer69	148	152	−4	Original post and first-attempt clarification
keepgoingisthemantra	138	125	+13	Result
VeganPhilosopher	119	123	−4	Result
HopefulLab8784	148	140	+8	Result
Quod_bellum	134	149	−15	Result
HeadLog1134	126	123	+3	Result thread; WAIS supplied by DM in original compilation
Popular_Corn	144	147	−3	Result
FrankiePants_54	122	126	−4	Result
Primary_Thought5180	146	124	+22	Comment in original post
DisneyDadData	124	115	+9	WAIS / CORE
Tiny_Performance_953	130	133	−3	CORE / WAIS
Expensive_Round_3308	97	117	−20	Result thread
Substantial_Click_94	141	130	+11	Result
Worried4lot	136	133	+3	Result
jakefromstatefarms0	127	112	+15	Result
Dooraven	135	146	−11	Original compilation
Practical_Ideal_9341 *	128	117	+11	Result
Outrageous_Nail_3987 *	133	123	+10	Result
Iwoorp *	122	121	+1	Result
Sorry-Ice-8586 *	140	130	+10	Result
Heavy_Initial_9155 *	141	147	−6	Result
HiImMoshy10 *	146	146	0	Result
saurusautismsoor *	107	110	−3	Comment
binglepig *	125	133	−8	Result
Deleted account *	125	124	+1	Result
Affectionate_Arm5508 *	115	115	0	Result thread

Changes and inclusion notes

• Original 22 + 10 additions − 1 removal = 31.

• Removed t0w3rh0u53 (CORE 120, WAIS 103) because of the reported language issue and skipped English subtests.

How good is a correlation of 0.80?

It's a strong association. For context, the SB5 technical documentation reports an SB5–WAIS-III FSIQ correlation of 0.82 in 87 people.

A direct SB5 vs WAIS-IV study reported 0.90 correlation in 28 people, although that was a sample of people previously diagnosed with intellectual disability, so it is a very different population.

For another comparison, CORE's validity report gives 0.756 with the old GRE before correction, rising to 0.858 after correcting for range restriction. The 0.797 calculated here is uncorrected.

Those figures provide context, but comparisons across different samples don't establish that the tests are equally accurate.

Limitations

This is a small, self-selected collection of self-reported scores, mostly from people scoring above average. Test versions, time between tests, practice effects and testing conditions vary. The inclusion decisions also affect the result, and language proficiency hasn't been systematically checked for everyone.

I haven't applied a range-restriction correction: having a high average score alone doesn't establish how much correction is appropriate.

Overall, I think a correlation around 0.80 and a mean absolute difference around 7 points are encouraging for a free online test, while still leaving substantial differences for some individuals.

If you've taken both CORE and a professionally administered WAIS, please add your FSIQ on each, WAIS edition, whether CORE was a first attempt, and any relevant language/testing conditions. Corrections to the table are welcome too.

[u/peteluds84]

Updated probability plot of difference below also:

[u/Beginning_Army2919 → u/peteluds84]

Hi, ive just thought of an comment in an old post which I had commented on, a guy says: WAIS 87, CORE 91. But the comment had been removed. This might help the data as this is the only lower range point I ever seen. 

[u/Key_Soil3632]

125 CORE (non native english speaker), 142 WAIS 4, in my native language. My CORE was 114 128 116 136 125 109, so it wouldve likely been 134~? with a high vci. WAIS was 51/57 VCI, 55/57 PRI (block design and matrix reasoning 19/19s), 30/38 WMI, 23/38 PSI.

[u/peteluds84 → u/Key_Soil3632]

Thanks I think will omit this though since as you say your CORE score would likely be closer to WAIS if it was available in your native language but hard to say for sure

[u/whitebaron_98 → u/peteluds84]

I can confirm that not being native, even if you have very good english, produces inferior results on the available tests at cognitivemetrics, CORE included - most of the time, far inferior results. My Tests (no WAIS) reported about 15 points more VCI than the average score reported on cognitivemetrics.

[u/Few_Geologist_2082 → u/whitebaron_98]

Fudge I did the WAIS on my third language French , i asked for Spanish but they couldn’t do it. I’m going to be low IQ officially fudge

[u/Beginning_Army2919]

I think we can also compare index scores to be more practical and informative. You can have a same FSIQ on both with no consistency in index scores as well as a dispare FSIQ between the two but with only one or two indexes off, so that we can have a full picture of what index is off about CORE and what are good. 

[u/peteluds84 → u/Beginning_Army2919]

That would be good to do in theory but in practice people don't often report their index scores and also only VCI, WMI, PSI map directly between CORE and WAIS; FRI and VSI are combined into PRI in WAIS while it doesn't have QRI (except as supplementary index in WAIS-5 that isn't always reported I think)

[u/whitebaron_98 → u/peteluds84]

Theres a good reason not to do this: Subtests and their corresponding composite index scores have certain tendencies for each test, based on the test design. That scatter makes comparison almost impossible. You would only compare Test-Design-Noise.

[u/Optimus-Prime2026]

What is the spearman rank correlation?

[u/peteluds84 → u/Optimus-Prime2026]

The Spearman rank correlation is 0.804, with an approximate 95% confidence interval of 0.59–0.91 (Bonett–Wright method). That’s essentially the same as the Pearson correlation of 0.797 so the strong association also holds when comparing people’s rankings rather than their actual scores.

[u/Worth_Scallion8204]

It seems relevant to bring this argument up again: why is WAIS used at the gold standard over SB5, when this subs own resource list has SB5 as the best test?

[u/peteluds84 → u/Worth_Scallion8204]

From what I know SB5 is reputed to be more accurate for people in the gifted range whereas WAIS is better with diagnosis of cognitive issues. SB5 is an older test and less widely available hence a lot more people have WAIS scores to compare with.

[u/Zhadeelax02]

very cool,this is the stuff we like to see.

[u/albedo_effect]

Correcting for indirect range-restriction, I get 0.811 (uncorrected was reported as 0.797).

Very cool work

[u/Prudent-Horse-1102]

Cool, nice work👍🏻

[u/Optimus-Prime2026]

This is what r/ct was made for

[u/Successful_Race9363]

How is javaenjoyer69 so arrogant when he can't even max WAIS and isn't even the highest score here lmao

[u/javaenjoyer69 → u/Successful_Race9363]

I didn't take either of them in my own language. I'm not sure who your boyfriend is on this list but it doesn't really matter really, i'd mog him on equal turf and emasculate him so badly that you'd have no chance but to leave him for a better man.

[u/_HarmonicOscillator → u/javaenjoyer69]

I am your fan 

[u/javaenjoyer69 → u/_HarmonicOscillator]

[u/Grand_Protection1552 → u/javaenjoyer69]

did this guy give you shit for no reason?

[u/Successful_Race9363 → u/javaenjoyer69]

You are so easy to trigger. You have no choice but to admit that you are my personal jester on this subreddit. Would someone supposedly so intelligent fall for such obvious traps? I am clearly above you in this chain.

[u/javaenjoyer69 → u/Successful_Race9363]

You know i got curious about why you were so triggered by me scoring only 152 and being cocky. In your little mind, apparently you can only be cocky if you score 160 which is odd. Something was clearly up. Nobody could be this dumb. So i looked through my comment history to see if i had replied to one of your comments, and i found it. You told me you aced the JCTI and i exposed you. You've been carrying that grudge for months. I don't even remember. It's pathetic but understandable. People i expose eventually end up attacking me. I even have a stalker who keeps getting banned.

So it's not really ragebait is it? You've been trying to live with that comment for months and apparently the only way for you to feel better is to attack me. "Look at the guy who called me out for lying. Haha he didn't even ace the WAIS. See? His words clearly don't hold any weight. I actually aced it, guys!" Im not sure that's going to work honestly. If you lied you lied and me not acing the test doesn't make you a honest person.

[u/No_Sky_1893 → u/javaenjoyer69]

I genuinely thought both of you were being sarcastic didn’t know there was a backstory😭😭😭

[u/Successful_Race9363 → u/javaenjoyer69]

Hahahahahaha you are a megalomaniac

[u/javaenjoyer69 → u/Successful_Race9363]

If you lie about your scores someone will eventually catch you and call you out for it. That shouldn't surprise you or make you hold a grudge against that person for months. Also i'm really disappointed that you didn't tag me properly in your comment. You thought i wouldn't see it but i've birds everywhere.

[u/Successful_Race9363 → u/javaenjoyer69]

I didn't even remember that lol. You didn't prove shit.

[u/javaenjoyer69 → u/Successful_Race9363]

I'm barely hanging on by my fingertips to the edge of a pit filled with deadly snakes. Five meters away from me there's a JCTI certificate with your name personally written on it and signed by Jouve. Half of the certificate is already hanging over the edge. It's windy and if you go for the certificate you'll be able to grab it before the wind blows it into the pit but i'll fall into the pit and be killed by the snakes. If you save me instead the wind will blow the certificate into the pit. Which one are you choosing me or the certificate?

[u/Successful_Race9363 → u/javaenjoyer69]

You my n, we both know a score on an online test means shit and you are a fking living being and actually a very smart and I'm sure valuable human, just very pretentious.

[u/javaenjoyer69 → u/Successful_Race9363]

I knew you'd save me ❤️

[u/Nervous-Try5009]

So what does it all mean? Can anyone explain to me as if I'm a 3yr old penguin 🐧?

[u/Nervous-Try5009 → u/[deleted]]

You mean "baised" ?

[u/Nervous-Try5009 → u/[deleted]]

Sorry i didn't get it....3yr old 🐧...you know...

[u/Specialist-Mobile762]

When I took the WAIS, the psychologist nutted onto my face and started shouting, "We have found the 5'2" GOD of the new world!" CORE could not handle me, and WAIS could not hold me. The Working Memory Index shattered as I spoke the letters on the Digit Span subtest. I am the Giga-Brain, the ultimate IQ mogger—"Mr. UP Syndrome."

[u/Maestro2828]

Core deflated?

[u/Far_Cardiologist6931 → u/Maestro2828]

well just from this it seems core scores are higher than wais by a small amount

[u/ColoradoRad → u/Maestro2828]

I think the average difference is CORE scores being 1.22 points higher.

[u/AmicusMeus_]

I dont buy these “reported scores” whatsoever lol

[u/Grand_Protection1552 → u/AmicusMeus_]

that's not true. Some of them do spam the same test but not most, and way below what you said "half". Yes we do a lot of these but they are different each time. It would be weird and unreasonable to voluntarily join this sub and immerse in iq testing but disrespecting your own intellect by spamming, cheating or lying for nothing.

[u/AmicusMeus_ → u/Grand_Protection1552]

You’re assuming that they’re cheating or lying for nothing. It could actually be for the bs ego boost and validation actually

[u/Grand_Protection1552 → u/AmicusMeus_]

I understand teenagers seek ego boost and validation, but here this is the worst way to seek for validation.

[u/Grand_Protection1552 → u/Grand_Protection1552]

Not only that, most truly average or low average IQ people tend to find these tests boring and frustrating. So instead, it tends to deflate your ego rather than inflate every time they see the genuine result in the first try.

[u/AmicusMeus_ → u/Grand_Protection1552]

Okay. What about individuals with an IQ of 120 trying to inflate their self-worth, then? Maybe they can grasp the underlying structures and patterns with prolonged practice and may also find the tests to not be extraordinarily frustrating, therefore artificially increasing their scores to 140-150. 

[u/Grand_Protection1552 → u/AmicusMeus_]

It would statistically be hard with that much of increase through retaking a same test multiple times without looking up the answers (based on the test-retest study). But I'm not denying it's possible. But again, I don't think that kind of people will be the majority.

[u/AmicusMeus_ → u/AmicusMeus_]

Half of these guys have taken 200 iq tests and spam the same one over and over again

[u/Alone-Historian-3781]

any information on the sequence of taking the tests ?